Shaving razors often comprise a lubricating strip to reduce friction between the razor and the skin of the person being shaved. The lubricating strips typically comprise a water soluble polymer, which upon exposure to water, begins to dissolve from the lubricating strip thereby reducing friction. It is not uncommon for such lubricating strips to be comprised of a polymer blend of poly(ethylene oxide) and polystyrene. Although such lubricating strips are functionally effective, the use of polystyrene has been viewed by the public to be undesirable due to the presence of an aromatic ring in the styrene and potential styrene emission problems.
Polyethylene is a polymer which does not contain an aromatic ring. Thus polyethylene would be a desirable substitute for polystyrene in such lubricating strips. However, prior to the present invention, molded polymer blends of polyethylene and poly(ethylene oxide) were not compatible, and thus could not readily form a substantially homogeneous blend. As a result, lubricating strips made from polyethylene and poly(ethylene oxide) often have a blotchy appearance, and more importantly, inconsistent lubricity characteristics due to the varying concentrations of poly(ethylene oxide). This characteristic is unacceptable in the marketplace.
Medical articles which are designed for insertion into the body, e.g. catheters, are often comprised of polyolefins, such as, polyethylene or polypropylene which are inherently non-lubricious. Attempts have been made to enhance the lubricity of such products when exposed to water by co-extruding the polyolefin substrate material with a hydrophilic polymer blend comprising a water soluble polymer such as, poly(ethylene oxide) and a carrier polymer which can adhere to the polyolefin substrate material, e.g., polyurethane.
Accordingly, in view of the need for lubricious-when-wet articles such as the razor lubricating strips and medical articles described above, improved polymer blends comprising polyolefins, e.g. polyethylene, and poly(alkylene oxides), e.g. poly(ethylene oxide), are desired. Such polymer blends would have utility in a variety of applications where lubricious-when-wet properties are desired.